DS1307 64 X 8 Serial Real Time Clock IC

DS1307 64 X 8 Serial Real Time Clock IC is an 8 pin device with a full binary-coded decimal (BCD) using 56 bytes of battery-backed SRAM. In this module address and data transferred serially through an I2C, bidirectional bus. The DS1307 operates as a slave device on the I2C bus. The DS1307 RTC module is a low-power clock providing seconds, minutes, hours, day, date, month and year qualified data. It automatically adjusts the end date of each month especially for months with less than 31 days, including the corrections of a leap year.

In the DS1307 RTC module, access obtained by implementing a START condition and providing a device identification code followed by a registered address. Until a STOP condition executed the subsequent registers accessed sequentially. The DS1307 RTC provides a battery back-up function that keeps the clock running even if there is a power failure. RTCs used in a wide range of applications like embedded systems and computer motherboards, etc.

The DS1307 provides an inbuilt power-sense circuit that detects power failures, as a result automatically switches to the backup supply. Timekeeping operation continues even though the module is operating from the backup supply. The DS1307 consists of an external 32.768 kHz crystal. There is no need for any external resistors or capacitors to operate the oscillator.

When VCC falls below 1.25 x VBAT, the device resets the device address counter and terminates access in progress. Inputs to the device will not be recognized at this time to prevent erroneous data from being written to the device from an out-of-tolerance system. Under the condition when VCC falls below VBAT, the device switches into a low current battery-backup mode. As soon as the power-up, the device switches from battery to VCC.